Please Note: A valid prescription is required to purchase a CPAP or BiPAP Machines. Every certified pre-owned machine undergoes thorough testing, cleansing, and sterilization before earning the certified pre-owned title. The maximum lifespan of a CPAP or BiPAP machines we’ve seen is 25,000 usage hours. All certified pre-owned are final sale. The machine will be supplied with new tubing, a new filter, and a new water chamber and SD Card. Be assured that your CPAP machine will reach you meticulously cleaned, tested, and accurately set for pressure. All sales are final!.